1. Field of the Invention
The field of the invention is that of reciprocating pneumatic power tools of the type adapted for sanding, rubbing, burnishing, etc.
2. Description of the Prior Art
The background in this type of tool is illustrated in the following U.S. Pat. Nos.:
______________________________________ 987,940 2,635,396 1,492,659 2,648,121 1,493,650 2,666,978 1,590,353 2,722,917 1,677,112 2,813,514 1,953,534 2,835,957 1,954,489 2,722,917 2,080,451 2,813,514 2,120,300 2,835,957 2,202,072 3,108,409 2,224,132 3,274,895 2,225,395 3,399,494 2,521,566 3,214,823 2,598,480 3,563,134 2,620,775 ______________________________________
Tools of the type of this application are known wherein a single shoe is driven by a pair of aligned or "in line" reciprocating pistons. An illustration of this type of tool is in U.S. Pat. No. 3,214,823. In the prior art tool the single shoe is driven by the pistons by way of rack and pinion gears, the pistons both moving in the same direction.
The areas or aspects of the prior art tools in which there has been room for improvement are that of the power of the tool for producing the reciprocating movement and in the amount of undesired vibration that is imparted to the tool by the reciprocating pistons. The manner in which these needs for improvement have been fulfilled are covered in the detailed description of the herein invention appearing hereafter.